Fill the porous ice melt sock with ice melt. Close the Velcro seal at the end so ice melt granules don't spill out.
Climb the ladder and place the sock over the ice dam so it lays with one end toward the peak of the roof and the other end draping into the gutter.
Place ice melt discs along the ridge of the ice dam. If you can see water pooled behind the ice dam, toss a disc into the water to dissolve.
Check on the ice melt sock every 30 to 60 minutes to ensure it's melting a channel into the ice dam. Once the channel is formed, the water behind the ice dam will flow into the gutter. Leave the ice melt sock and discs in place to prevent other dams from forming.